Arbor chuck



Jan; 1945. H. R. FEICHTER 2,366,778

ARBOR CHUCK Filed June 18, 1942 Fig. 1

- Fig. 4

Ha'I'0ldfl.Feichier Patented Jan. 9, 1945 ARBOR CHUCK Harold R. Feichter, Canton, Ohio, assignor to United States Quarry Tile Company, Canton,

Ohio, a corporation of Delaware Application June 18, 1942, Serial No. 447,545

Claims.

My invention relates to arbor chucks, and more particularly to arbor chucks for use in polishing ceramic spark plug insulators of the type set forth in my application for United States Letters Patent for Spark plug manufacture, filed May 20, 1942, Serial No. 443,733, now Patent No. 2,351,029, issued June 13, 1944.

The ceramic spark plug; insulators shown in said application, Serial No. 443,733, include a fired ceramic body having a generally tubular form and on which certain of its fired surfaces are made smooth by mechanical polishing to remove the usual projections formed after firing and which projections surround pits.

By mechanical polishing the selected surfaces of such a ceramic spark plug insulator, the projections are reduced and the polished surfaces on the body, such as the tip, nose, and shoulder surfaces-are smooth and substantially free from the projections and intervening pits, for attaining the advantages set forth in said application, and including facilitating the seal of the insulator at its shoulders in its metal shell in the spark plug of which it is apart, and minimizing deposit of carbon on its tip and nose and facilitating cleaning the tip and nose.

The material of such an insulator is preferably very hard, approaching the hardness of a diamond, but is subiect to fracture when gripped by the metal laws of a usual chuck.

The objects of the present invention include the provision of an improved arbor chuck adapted for securely gripping the neck of a ceramic spark plug insulator and the like, without slippin during subsequent polishing op rations, and without present invention may be stated in general terms as including a shank preferably adapted for be ing pped-by the metal jaws of a usual lathe chuck or the like.

I An arbor or mandrel extends from one end of the shank which is the outer end when the shank is gripped by'the laws of a lathe chuck or the like.

The outer end of the shank has formed thereon external threads, and a clamp sleeve nut has in one of its ends internal threads which screw on the shank threads, and has an annular clamp flange on its other or outer end.

The central preferably circular opening defined by the clamp flange is slightly larger in diameter than the diameter of the neck of the insulator or workpiece which fits on the arbor. I

Between the clamp flange of. the nut and th outer end face of the shank, are located one or more rubber washers each having a substantial thickness, and the arbor thus extends through therubber washers and clamp sleeve nut.

Each rubber washer is shaped to accurately fit the interior of the clamp nut and the exterior of the insulator or other workpiece gripped in the improved arbor chuck by tightening the clamp nut and compressing the rubber washers spark plug insulator, the arbor chuck being gripped by jaws, shown in fragmentary form, of

a lathe chuck or the like;

Fig. 2, a view similar to Fig. 1, showing the use of two rubber washers in the improved arbor chuck instead of the single rubber washer shown in Fig. 1, and showingthe parts before the placing of the ceramic spark plug insulator on the arbor and insertion into the hole of the rubber washers;

Fig. 3, a fragmentary transverse view thereof Fig. 4, a detached elevation view of themsulator shown being gripped in the improved arbor chuck in Fig. 1.

Similar numerals refer to similar parts throughout the several views.

The ceramic spark plug insulator indicated generally by M is generally tubular in form, and

serial No. 443,733, it is necessary to secure the the insulator to for rotation, preferably about its longitudinal axis.

The material of the ceramic spark plug insulator it particularly when made with a body as described in said application Serial No. 443,733, is very hard, approaching the hardness of a diamend, but is subject tofracture or crushing when a bore in the shank and locating the inner end of As shown and preferably,

the arbor in the bore. the arbor I4 is externally cylindrlc. v H A g The outer end of the lTl'l'as' formed thereon external threads IS.

A clamp sleeve nut l6 has in one end internal threads I! which screw on the shank threads l5. and the sleeve nut [B has on its other end an annular clamp flange l8. The central circular opening l9 defined by the flange II is slightly larger in diameter than the diameter of the cylindric neck 20 of the insulator II as shown which fits on the cylindric arbor ll preferably with the end face of the neck 20 abutting the outer end face of the shank l2.

Within the sleeve nut 16 and between the flange 88 thereof and the outer end face of the shank i2, one or more resilient washers 2| are located.

The washers 2| are preferably made of rubber and have holes which must be accurately punched in true form, usually circular or cylindric, to flt the cylindric neck 20 of the insulator l0, and likewise the outer peripheries of the'rubber washers :i must be of true form, preferably circuit or cylindric, to fit the preferably cylindric bore of the clamp sleeve nut l6.

, The arbor l4 thus extends through the rubber washers II and the clamp sleeve nut It.

In using the improved arbor chuck II, the sleeve nut I6 is loosened on the threads l5, and an insulator III is inserted on the arbor 14 through the flange opening l9 and the holes of the washers 2| with the inner end of the neck 20 of the insulator l abutting the outer end face of the shank l2.

The nut It is then screwed up or tightened on. the threads l compressing the rubber washers 2| and causing a gripping action of the surfaces of the holes of the rubber washers on the neck II of the insulator Ill and between the outer surfaces of the washers 2| and the inner surfaces of the sleeve nut l6 and the outer end face of the shank II.

The insulator I0 is thus gripped securely in the improved chuck ll without slipping duringthe subsequent polishing operations, and without fracturing or crushing. The arbor 14, however, utends through the rubber washers 2|, and be ing coaxial with the shank 12, serves to maintain the tubular insulator ill for rotation about its longitudinal axis, as is necessary during the polishing operations.

The polishing or other operations performed on the ceramic spark plug, insulator In as thus secured in the improved chuck I I may be according to usual lapping operations as set forth in ll. Also from a broad standpoint, the cylindric bore surface of the clamp sleeve nut l6, and the outer peripheral surface of the resilient annular members 2| may be described as abutting surfaces of trueform and extending longitudinally of the arbor and being radially spacedtherefrom, the abutting surfaces fitting each other when the resilient member is uncompressed.

"Th'e'eni'iicidifnients" of the present invention illustrated and described-herein are by way of example, and the scope of the present invention is not limited to the same or to the particular details thereof but is commensurate with any and all novel subject matter contained herein which may at any time properly under the United States patent laws be set forth in the claims he'r'ebf or originating herein, and the elements of any such claims are intended to include their functional or structural equivalents.

I claim:

In an arbor chuck adapted for gripping and securinga tubular member of ceramic material and the like for rotation without slipping when subject to polishing operations and the like and without crushing or fracturing, a shank adapted for rotation about an axis, screw threads on the shank, a clamping sleeve having screw threads coacting with the shank threads and having an annular. clamping flange spaced from an adjacent end of the shank, a resilient annular member within the clamping sleeve between the clamping flange and the adjacent end' of the shank, the clamping flange and the resilient annular member having central openings, and an arbor extending from the end of the shank adjacent the clamping flange and through the openings of the resilient annular member and the clamping flange, the resilient annular member having its outer periphery fitting with true form the interior of the clamping sleeve when the resilient annular member is uncompressed by the clamping sleeve, and the opening of the resilient annular member being sized to lit with true form the outer surface of a tubular member fitting on the arbor and having an end extending through the openings of the clamping flange and the resilient annular member.

2. In an arbor chuck adapted for gripping and securing a tubular member of ceramic material and the like for rotation without slipping when subject to polishing operations and the like and without crushing or fracturing, a shank adapted for rotation about an axis, screw threads on the shank, a clampingsleeve having screw threads coacting with the shank threads and having clamping flange means spaced from an adjacent end of the shank, resilient annular means within the clamping sleeve between the clamping flange means and the adjacent end of the shank, the clamping flange means and the resilient annular means having central openings, and an arbor extending from the end of the shank adjacent the assure v I theabutting surfaces fltting each other when the the interior of the clamp sleeve when the resilient annular means is by the clamping sleeve, and the opening of the resilient annular means being sized to flt with-true form the outer surface of a tubular member fltting on the arbor and having anend extending through the openings of the clamping flange means and the resilientannular means.

3. In an arbor chuck adapted for gripping and v securing a tubular member of ceramic material and the like for rotation without slipping when subject to polishing operations and the like and without crushing or fracturing, a shank adapted for rotation about an axis,clamping sleeve means adjacent one end of the shank and having annular clamping flange means spaced from the adjacent end of the shank, screw means associated with the shank and the clamping sleeve means for varying the position of the sleeve with respect to the shank, resilient annular means within the clamping sleeve means between the clamping flange means and the adjacent end of the shank, the clamping flange means and the resilient annular means having central openings, and an arbor extending from the end of the shank adjacent the clamping flange means and through the openings of the resilient annular means and the clamping flange means, the resilient annular means having its outer peripheral portions fltting with true form the interior of the clamping sleeve means when the resilient annular means is uncompressed by the clamping sleeve means, and the opening of the resilient annular means being sized to flt with true form the outer surface of a tubular member fltting on the arbor and having an end extending through the openings of the clamping flange means and the resilient annular means.

4. In an arbor chuck adapted for gripping a tubular member of ceramic material and the like, a shank adapted for rotation about an axis, external screw threads at one end of the shank, a clamping sleeve having a bore with internal screw threads coacting with the external shank screw threads and having an annular clamping flange spaced from the threaded end of the shank,

a resilient annular member fltting with true form in the bore of the sleeve between the clamping flange and the threaded ends of the shank, the clamping flange and the resilient annular member having central openings, and an arbor extending from the threaded end of the shank through the openings of the resilient annular member and the clamping flange, and the cenresilient member is uncompressed.

8. In arbor chuck adapted for gripping a tubular member of ceramic material and the like, an arbor adapted for iittingin the bore of a tubular member, a resilient member having an opening therethrough of true form with respect to the outer surface of the arbor, thearbor extending through the resilient member opening, means for compressing the resilient member and gripping a tubular member fltting on the arbor and-extending through and fitting the opening of the resilient member, the compressing means and the resilient member having abutting surfaces of true form and extending longitudinally of the arbor and being radially spaced therefrom, the abutting surfaces fltting each other when the resilient member is uncompressed, and means connected with the arbor and compressing means and adapted for rotation and for rotating the arbor and compressing means with each other.

'7. In an arbor chuck adapted for gripping a tubular member of ceramic material and the like, an arbor adapted for fitting in the bore of a tubular member, a plurality of resilient members each having an opening therethrough of true form with respect to the outer surface of the arbor, the arbor extending through the openings of the resilient members, means for compressing the resilient members and gripping a tubular member fitting on the arbor and extending through and fitting the openings of the resilient members, the compressing means and the resilient members having abutting surfaces of true form and extending longitudinally of the arbor and being radially spaced therefrom, the abutting surfaces fitting each other when theresilient member is uncompressed.

8. In an arbor chuck adapted for gripping a tubular member of ceramic material and the like, an arbor adapted for fitting in the bore of a tubular member, a pluralit of resilient members each having an opening therethrough of true form with respect to the outer surface of the arbor, the arbor extending through the openings of the resilient members, means for compressing the resilient members and gripping a tubular member fltting on the arbor and extending through and fltting the openings of the resilient ting surfaces fltting each other when the resilient tral opening of the resilient annular member having a true form with respect to the outer surface of the arbor.

5. In. an arbor chuck adapted for gripping a tubular member of ceramic material and the like, an arbor adapted for fltting in the bore of a tubular member, a resilient member having an opening therethrough of true form with respect to the outer surface of the arbor, the arbor extending through the resilient member opening, means for compressing the resilient member and gripping a tubular member fltting on the arbor and extending through and fltting the opening of the resilient member, the compressing means and the resilient member having abutting'surfaces of true form and extending longitudinally of the arbor and being radially paced therefrom,

member is uncompressed, and means connected with the arbor and compressing means and adapted for rotation and for rotating the arbor and compressing means with each other.

9. In an arbor chuck adapted for gripping a tubular member of ceramic material and the like, a cylindric arbor adapted for fitting in the cylindric bore of a tubular member, an external- -ly cylindric resilientmember having a cylindric opening therethrough of true form with respect to the outer cylindric surface of the arbor, the arbor having a smaller diameter than and extending through the resilient member cylindric opening, means for compressing the resilient the y ,lnciric gre gtthefisleeve when-theresllient member-1s uniiofniirssed.

10. In an arbor chuck adapted for gripping a tubular memberof ceramic material and thelikeq v a cylindric arbor adapted for fitting in the cylindric bore of a tubular member, an externally cy-' lindric resilient member having a cylindric open ing therethrough of true form with respect to the outer cylindric surface 01' the arbor," the arbor having a smaller diameter than and extending through theresilient member cylindric opening.

means for compressing the resilient member and gripping a tubular member fitting on the arbor of the resilient member, the com means including a sleeve around th'e re'silient member andthe arbor and having a cylindric bore,

pressed, and means connected with the arbor and compressing means and adapted torrotation-and for rotating the arbor and compressing means with each other.

HAROLD rt mcn'rm 

